Rinse oysters in cold salted water. Remove shell bits and pat completely dry with paper towels.
In a bowl, mix sweet potato starch with water until smooth and slightly runny.
Add fish sauce, white pepper, and chopped chives to the batter. Stir gently.
Fold oysters carefully into the batter without breaking them.
Heat oil in a wok over high heat until nearly smoking.
Pour batter into the pan and spread thin. Cook 1 minute until bottom turns golden and crisp.
Pour beaten eggs over and around the pancake. Let set briefly.
Flip quickly and add a little extra oil around the edges.
Cook another 1–2 minutes until golden and crispy.
Serve hot with garlic chili sauce or sweet chili sauce.